The present invention is related to a rotor structure of pneumatic grinder, which has higher strength.
FIG. 9 shows a conventional plastic rotor structure made by injection molding. The rotor structure has a rotor main body 6 formed with a central shaft hole 61. A rotary shaft (not shown) is fitted through the shaft hole 61. Several radial sector sections 62 are formed on outer circumference of the rotor main body 6 at equal intervals. Each sector section 62 has a depression 63 for reducing the weight of the rotor. A split 64 is defined between each two adjacent sector sections 62. A vane 65 is inserted in each split 64.
The rotor structure is mounted in a pneumatic tool. The vanes 65 bear the air pressure coming from the intake of the pneumatic tool for driving the rotor main body 6 to rotate.
During rotation of the rotor, high air pressure is applied to the vanes. Under such circumstance, the inner ends of the vanes in the splits will exert a very great action force onto the bottom ends of the sector sections. As a result, it often takes place that the bottom ends of the sector sections of the rotor main body fissure. Under such circumstance, the rotor main body will become useless.
Accordingly, it is tried by the applicant to provide a rotor structure having high strength to solve the above problem.